Serial Numbers Filed Off
When a Follow the Leader seems to be almost exactly like the leader, just with "the Serial Numbers Filed Off". The blatant copying of characters and plot is on a level that would make even makers of The Mockbuster blush. Although that need not mean the quality is bad.
Named because some stolen goods (particularly firearms) would have the serial numbers filed off to make them untraceable.
Contrast Dolled-Up Installment, In Name Only (both are when a work seems to have the serial numbers of another work scribbled on), Shoddy Knockoff Product (a ripoff that seeks to look like a work, but is a very poor copy).
No examples, please; If we started listing examples here, we'd be here all day. Feel free to link to this page from works pages, though.